Sound muffling device for typewriters and other machines



J. T. HUMES Aug. 2, 1932.

SOUND MUFFLING DEVICE FOR TYPEWRI TERS AND OTHER MACHINES Filed Dec. 27, 1950 I amulet =Ja27ve6 ZV/vme;

Fetented Ange i932 untrue stares PATENT JAMES? 'i. EUEXES, 3F HABRISQNBURG, "VIRGINIA Application filed December 2?, 1930. Serial Ito. coarse.

My invention relates to sound mufliing devices for typewriting and other machines, and has for its object to provide a device which will absorb shocks and will mufiieor deaden sounds produced by a typewriting machine or other key operated machine, such as. a calculating machine or check protector.

A further object of my invention is to provide a device for such purpose which it? will be simple and inexpensive in construction and will be adapted for use with machines of difierent makes.

With the objects above indicated my invention consists in the construction and it; combination of elements hereinafter described and claimed.

Referring to the drawing:

Figure 1 is a perspective view of a complete pad embodying my invention.

Figure 2 is a cross sectional view on line :22 of Figure l.

Figure 3 is a perspective top view of one of the supporting devices for the legs of a typewriting machine, and

Figure a is a perspective bottom view of the supporting device.

in the drawing 1 indicates a sheet of thick resilient material, preferably of spongy rubher, such as is sometimes used. as a pad to support a typewriter or other machine on a desk or table. This sheet of material or pad is somewhat greater in area than the area of the base of the typewriter or other machine; is preferably from one quarter to one half inch in thickness, and has a smooth upper surface. Used by itself as a support for the typewriter or other machine the feet 2 of the machine form depressions in the pad and so compress the spongy rubber that it ceases to afford the resilience desired. For the purpose of maintaining the original resilience of the pad and further increasing the resilience of the support for the typewriting machine, I arrange onthe pad 1 at the four points required for the four feet 2, sup;

ports 3 so constructed as to afiordin themselves resilient supporting means but also to serve to distribute the weight of the typewriting or other machine both vertically and horizontally, and to protect the relative- 5O ly soft surface of the underlying pad from depressions which the legs 2 would form in a pad used by itself. I

These supporting devices 3 are formed preferably of rubber or rubber compound so vulcanized as to be relatively hard but elastic such as the rubber compound used for vehicle tires, and are so formed as to have on their upper faces a recess 4 adapted to raise the foot 2 of the typewriting or other machine preferably of such area as to allow for diiferences in the size and relative positions of the feet of machines of different makes. From the margins of these recesses extend sloping sides 5 and ends 6 to edges 7 and 8. On their under sides extending a short distance inward from edges 7 and 8, are flat faces 9 and 10 of sufficient Width to afford a substantial hold for cement 11, by which theyare secured on the surface of the pad 1. From the inner edges of those flat faces 9 and 10, side and end faces 12 and 13 extend upward and inward to a central rectangular face i l concentric with, but of less area than the area of the recess 4 from which it is separated by a substantial. thickness of the material of which the supporting device is formed.

The supporting devices 3 are arranged on pad 1 in proper position to each receive one of the legs 2 and the flat faces 9 and 10 are secured by cement ll, to the upper smooth surface of the pad, thus enclosing in the rccess space formed by the inclined under faces 12 and 13 and horizontal face 14 a body of air to aid in the resilience of the supporting device. The pressure of the legs on the bottoms ofrecesses 4 is resisted by the resilience of the supporting device itself aided by the resistance of the body of air enclosed between their under surface and the upper surface of the pad 1. Thesupporting device is itself resiliently supported against vertical depression by the portion of the pad on which it rests and any tendency of the supporting device to be spread by the weight of the machine is, by reason of the union of the flat faces 9 and 10 with the upper surface of the pad, resiliently resisted by the resistance of the pad to stretching.

The supporting devices are so constructed that the weight of the machine will cause yielding both vertically and horizontally and this yielding will be resisted resiliently by the supporting devices themselves and by the material of the pad.

The support thus afforded is particularly effective in absorbing shocks and mufiling or deadening sounds produced by operation of the keys and carriage of a typewriting machine, and also gives to the keys a resilient touch particularly desirable to the operator.

Having thus described my invention, what I claim is:

1. A sound muflling device for typewriting and other machines comprising a pad of resilient, readily yielding material of an area as great as that of the base of the typewriting or other machine, and leg supporting devices on the upper face of the pad of a relatively rigid material less yielding than the material of the pad, each having its upper face adapted to receive a leg of the typewriting or other machine and having its base of greater area than its upper face. I

2. A sound mufiling device for typewriting and other machines comprising a pad of resilient, readily yielding material of an area as great as that of the base of the typewriting or other machine and leg supporting devices on the upper face of the pad of a relatively rigid material less yielding than the material of the pad each havin its upper face adapted to receive a leg of the typewriting or other machine and having its base of greater area than its upper face, and having the edges of its base cemented to the upper face of the pad.

3. A sound muifling device for typewriting and other machines comprising a pad of resilient readily yielding material of an area as great as that of the base of the typewriting or other machine and leg supporting devices on the upper face of the pad of a relatively rigid material less yielding than the material of the pad, each supporting device having in its up per face a recess adapted to receive a leg of the machine, having its base of greater area than said recess, having the edge portion of its lower face adapted to rest on the pad and having in its lower face an upwardly extendmg recess. v

4. A sound mufiiing device for typewriting and other machines comprising a pad of resilient readily yielding material of an area as great as that of the base of the typewriting or signature.

JAMES T. HUMES.

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